Nowadays the use of laundry washing machines, both “simple” laundry washing machines (i.e. laundry washing machines which can only wash and rinse laundry) and washing-drying machines (i.e. laundry washing machines which can also dry laundry), is widespread.
In the present description the term “laundry washing machine” will refer to both simple laundry washing machines and laundry washing-drying machines.
Laundry washing machines generally comprise an external casing provided with a washing tub inside which there is a rotatable perforated drum in which the laundry is placed.
A loading/unloading door ensures access to the tub and the drum.
Laundry washing machines typically comprise a detergent supply unit containing washing and/or rinsing products (i.e. detergent, softener, etc.) and a water inlet circuit for supplying water. The detergent supply unit, usually consisting of a removable drawer, and the water inlet circuit preferably co-operate to allow the introduction of the water and the washing/rinsing products into the tub during the laundry washing cycle.
A washing cycle typically includes a first phase, or wetting phase, during which a pre-determined quantity of detergent is put inside the tub on the laundry together with a quantity of wetting water.
The water is supplied into the tub by making it flow through the drawer. In this way the introduction of the prefixed quantity of detergent is brought out of the apposite compartment of the drawer by the flow of clean water that passes through the proper compartment of the drawer itself.
According to a known technique, the initial wetting phase includes the step of mixing a predetermined amount of detergent with water to form a solution which is introduced in the tub for wetting the laundry.
A wetting method belonging to the know technique is disclosed in document EP864684A1. In this document a method and a system for dosing detergent to a washing machine is described.
The dosing system comprises a supply holder for detergent and a mixing chamber for mixing the detergent with a solvent (preferably water) in a predetermined concentration range to form a liquor. The system also comprises control means for supplying the content of the mixing chamber to a remote washing machine once the liquor is prepared inside the mixing chamber. A dose controlling unit is further connected to a pump disposed in the line between the mixing chamber and the remote washing machine in order to ensure that the desired amount of detergent is supplied to the washing machine.
However, the system for mixing detergent with water above described belonging to the known art poses some drawbacks.
A first drawback posed by this known technique is constituted by the complexity of the system for mixing detergent with water.
A further drawback of the known technique is represented by the fact that the system for mixing detergent with the solvent is cumbersome.